1. FIELD OF THE INVENTION
The present invention relates to a fault diagnostic device for a winding of an electric machinery and apparatus for detecting fault or undesired holding condition of the winding of the electric machinery and apparatus (hereinafter referring to as electric instrument) such as a winding in a stator, a rotor or an armature of a rotary electric machine.
2. DESCRIPTION OF THE PRIOR ART
Recently, it is significant to improve electric instrument such as rotary electric machines in view of an increase of a capacity of an electric instrument and a compact light weight size. Thus, windings of the electric instruments should be used in severe conditions. In such conditions, higher reliability is required for electric instruments especially rotary electric machines in view of power demands and supply shortage and prolonged period for periodical inspection, etc.
On the other hand, an increase of a capacity of a rotary electric machine and a prolonged period for exchange of a rotary electric machine should be considered in view of economical depression. Superannuated (overaged) rotary electric machines have been used.
It is quite important to perform diagnoses of fault of windings or undesired holding condition of windings by non-destructive inspection in view of confirmation of reliability of windings of old instruments and fault prevention and maintenance thereof.
In the diagnoses of fault of windings of electric instruments such as rotary electric machines, appearance inspections, hammering inspection, etc. have been carried out so as to find fault of the windings. Therefore, in the inspection, it mostly depends upon operator's experience. In such manner, it is not enough to give objectivity of informations or data for finding fault of the windings. It is difficult to measure directly values for functions and accordingly, various methods of finding substituted values have been carried out. Therefore, it has required to work for experimental measurements for a long period in order to consider it from certain data by inductive methods. There is no possibility to estimate a feature condition by the result of consideration of data measured for the inspection or the study of the condition.